• Korean Chemical Engineering Research
• /
• v.58 no.3
• /
• pp.424-429
• /
• 2020

An Energy Storage System (ESS) is recently drawing an increasing attention as an efficient tool to cope with variation in the energy system. In order to take the best utilization of ESS, the inherent variation of energy supply and demand should be properly addressed. This paper is concerned with computing the stochastic capacity of ESS in the face of such variations by way of Monte Carlo simulation. The issue of uncertainty in energy systems will be given further focus. More works are expected to be followed to address the issues in academia and industry.

• KEPCO Journal on Electric Power and Energy
• /
• v.2 no.2
• /
• pp.285-291
• /
• 2016

In chemical-looping combustion, pure oxygen is transferred to fuel by solid particles called as oxygen carrier. Chemical-looping combustion process usually utilizes a circulating fluidized-bed process for fuel combustion and regeneration of the reduced oxygen carrier. The performance of an oxygen carrier varies with the active metal oxide and the raw support materials used. In this work, spraydried Mn-based oxygen carriers were prepared with different raw support materials and their physical properties and oxygen transfer performance were investigated to determine that the raw support materials used are suitable for spray-dried manganese oxide oxygen carrier. Oxygen carriers composed of 70 wt% $Mn_3O_4$ and 30 wt% support were produced using spray dryer. Two different types of $Al_2O_3$, ${\gamma}-Al_2O_3$ and ${\alpha}-Al_2O_3$, and $MgAl_2O_4$ were applied as starting raw support materials. The oxygen carrier prepared from ${\gamma}-Al_2O_3$ showed high mechanical strength stronger than commercial fluidization catalytic cracking catalyst at calcination temperatures below $1100^{\circ}C$, while the ones prepared from ${\alpha}-Al_2O_3$ and $MgAl_2O_4$ required higher calcination temperatures. Oxygen transfer capacity of the oxygen carrier prepared from ${\gamma}-Al_2O_3$ was less than 3 wt%. In comparison, oxygen carriers prepared from ${\alpha}-Al_2O_3$ and $MgAl_2O_4$ showed higher oxygen transfer capacity, around 3.4 and 4.4 wt%, respectively. Among the prepared Mn-based oxygen carriers, the one made from $MgAl_2O_4$ showed superior oxygen transfer performance in the chemical-looping combustion of $CH_4$, $H_2$, and CO. However, it required a high calcination temperature of $1400^{\circ}C$ to obtain strong mechnical strength. Therefore, further study to develop new support compositions is required to lower the calcination temperature without decline in the oxygen transfer performance.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.7 no.4
• /
• pp.98-108
• /
• 2004

The concept of community capacity is regarded as the ability of people and communities to do works associated with the determinant factors and indicators of the circumstances of socio-economic, environmental and physical contexts. Building capacity of communities to effectively analyze our problematic issues and planning of community development is often required to scrutinize current status of community of socio-economic and infrastructural capacity development with GIS. We consider community development as a planned effort to build assets that increase the capacity of communities. Spatial asset mapping is the process enabling to identify and make inventories of tangible and intangible assets. This mapping requires developing a capacity inventory that collects individual organizational and community capacities in view of human, socio-cultural, natural, financial, digital, and physical capacity. The purpose of this research is not only designed to suggest a new concept capacity building, but also proposes a more creative framework of asset-based community cap linking to parcel-based spatial asset mapping and capacity mapping process.

• ETRI Journal
• /
• v.36 no.3
• /
• pp.374-384
• /
• 2014

To achieve high-speed (giga-bit) connectivity for short-range wireless multimedia applications, the millimeter-wave (mmWave) wireless personal area networks with directional antennas are gaining increased interest. Due to the use of directional antennas and mmWave communications, the probability of non-interfering transmissions increases in a localized region. Network throughput can be increased immensely by the concurrent time allocation of non-interfering transmissions. The problem of finding optimum time allocation for concurrent transmissions is an NP-hard problem. In this paper, we propose two enhanced versions of previously proposed multi-hop concurrent transmission (MHCT) schemes. To increase network capacity, the proposed schemes efficiently make use of the free holes in the time-allocation map of the MHCT scheme; thus, making it more compact.

• STI Policy Review
• /
• v.4 no.1
• /
• pp.1-13
• /
• 2013

The Schumpeterian process of "creative destruction", associated with the emergence and diffusion of new radical, so-called "general purpose" technologies, has throughout history impacted wealth and income, jobs creation, jobs displacement, and the emergence and submergence of new hotspots of innovation. Emerging countries have benefited most from such a renewing of those societies' dynamics, leading them to higher levels of economic development and welfare. Doing so they have shown a remarkable capacity in moving upstream in the value chain, from outsourcing of manufacturing activities to autonomous process technology development, product development, design, and applied research. At the same time however, such Schumpeterian processes have now and then turned into exactly opposite processes of "destructive creation." Such processes seem to have become common among what could be called "submerging" economies: innovation only benefitting a few at the expense of many with as a result an opposite pattern of a long term reduction in overall welfare, productivity, and employment growth.

• Journal of Microbiology and Biotechnology
• /
• v.33 no.8
• /
• pp.992-997
• /
• 2023

Ferroptosis is a new kind of programmed cell death of which occurrence in microorganisms is not clearly verified. The elevated level of reactive oxygen species (ROS) influences cellular metabolisms through highly reactive hydroxyl radical formation under the iron-dependent Fenton reaction. Iron contributes to ROS production and acts as a cofactor for lipoxygenase to catalyze poly unsaturated fatty acid (PUFA) oxidation, exerting oxidative damage in cells. While ferroptosis is known to take place only in mammalian cells, recent studies discovered the possible ferroptosis-like death in few specific microorganisms. Capacity of integrating PUFA into intracellular membrane phospholipid has been considered as a key factor in bacterial or fungal ferroptosis-like death. Vibrio species in bacteria and Saccharomyces cerevisiae in fungi exhibited certain characteristics. Therefore, this review focus on introducing the occurrence of ferroptosis-like death in microorganisms and investigating the mode of action underlying the cells based on contribution of lipid peroxidation and iron-dependent reaction.

• Journal of Korea Game Society
• /
• v.21 no.2
• /
• pp.139-150
• /
• 2021

This study analyzed the effectiveness by developing an online program to enhance collaborative problem-solving capabilities for college freshmen using gamification. According to the research results, the operational model of the online program for enhancing collaborative problem-solving capabilities using gamification was presented in five stages: 1 preparation, 2 team building, 3 assessment, 4 feedback, and 5 achievement sharing. The results of the "pre-test" and post T-test of creative problem-solving capabilities, the variables related to creative problem-solving skills, academic challenge, creative thinking ability, and convergence value creation have been significantly improved. What should be discussed in the future is the need to experience collaborative problem solving process online, and to develop game design and platform that can discuss and communicate.

• Journal of the Korean Society for Library and Information Science
• /
• v.57 no.3
• /
• pp.143-161
• /
• 2023

The purpose of this study was to investigate whether students' creative problem-solving skills improve through project-based courses. Rather than measuring overall competencies, the focus was specifically on measuring the improvement of problem-solving skills. The study involved a literature review, the design of project-based courses, and the assessment and analysis of students' competencies before and after the courses. The results of the study are as follows: Firstly, the measurement of students' creative problem-solving skills before and after the project-based courses indicated an overall improvement in the five dimensions of problem identification, analytical thinking, flexible thinking, alternative generation, and a proactive attitude. Secondly, significant correlations were found among these five dimensions, particularly strong correlations were observed between problem identification and alternative generation, problem identification and analytical thinking, and analytical thinking and alternative generation. To generalize the findings of this study, further research is needed to apply similar approaches in different types of courses and across various universities and departments.

• Journal of Creative Information Culture
• /
• v.5 no.3
• /
• pp.215-223
• /
• 2019

The wave of the information age gradually accelerates, and fusion analysis solutions that can utilize these knowledge data according to accumulation of various forms of big data such as large capacity texts, sounds, movies and the like are increasing, Reduction in the cost of storing data accordingly, development of social network service (SNS), etc. resulted in quantitative qualitative expansion of data. Such a situation makes possible utilization of data which was not trying to be existing, and the potential value and influence of the data are increasing. Research is being actively made to present future-oriented education systems by applying these fusion analysis systems to the improvement of the educational system. In this research, we conducted a big data analysis on Twitter, analyzed the natural language of the data and frequency analysis of the word, quantitative measure of how domestic windows education problems and outcomes were done in it as a solution.

• International Journal of Contents
• /
• v.6 no.2
• /
• pp.14-20
• /
• 2010

Korean Cultural Content Industry is developing creative cultural content based on internationally acknowledged manufacturing capacity, however, in order to become cultural industry with international competitiveness, it has to be planned and made in OMSU way. This research studied and analyzed successful cases of cultural content digital restoration and excellent cases of OSMU-type that has been developed and supported by Korean Culture and Contents Agency. This study suggests the direction of growth on the basis of movement of cultural content industry and cultivating plan of human resources.